TEA5777HL/N2 STEricsson, TEA5777HL/N2 Datasheet - Page 12
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TEA5777HL/N2
Manufacturer Part Number
TEA5777HL/N2
Description
Manufacturer
STEricsson
Datasheet
1.TEA5777HLN2.pdf
(48 pages)
Specifications of TEA5777HL/N2
Lead Free Status / Rohs Status
Supplier Unconfirmed
Philips Semiconductors
TEA5777_1
Product data sheet
8.1.5 AM IF filter
8.1.6 AM IF amplification and AM detection
8.2.1 Low noise RF amplifier
8.2.2 FM I/Q mixer
8.2 FM radio part
High-side injection or low-side injection of the VCO can be chosen:
The AM circuit incorporates an I and Q orthogonal channel path with fully integrated
polyphase IF filter. All AM IF filtering is done inside the IC, therefore no external filter
components are required. The center frequency of the filter is 21 kHz and the 3 dB
bandwidth amounts to 8 kHz.
The IF AGC controls the IF amplification and a fully integrated AM detector converts the
AM IF signal into audio. In AM mode the capacitor connected to pin AGC2CAP is used for
IF AGC filtering. The value of this capacitor is a compromise between AGC speed and
THD. In order to achieve an acceptable THD in normal mode and an acceptable AGC
response during e.g. a search action, the time constant can be switched to a value
15 times lower by means of bit AGCIF. In autonomous search mode (bit SEARCH = 1) the
time constant is switched automatically to the lowest value.
The FM circuit incorporates a wideband input. The LNA input impedance together with the
LC RF input circuit defines a low Q, FM band-pass filter. The input filter is also used for
impedance matching between the source impedance and the 300
impedance between pins RFIN1 and RFIN2. An RF AGC circuit prevents the mixer and IF
filter from overdrive conditions.
FM quadrature mixers, in an orthogonal I/Q architecture, convert FM RF signals to the
internal f
rejection. Whether f
For choosing the best signal conditions with respect to the influence of the image signals,
high-side or low-side injection can be selected:
•
•
•
•
High-side injection: local oscillator frequency at mixer input is higher than RF input
signal frequency.
Low-side injection: local oscillator frequency at mixer input is lower than RF input
signal frequency.
High-side injection: local oscillator frequency at mixer input is higher than RF input
signal frequency.
Low-side injection: local oscillator frequency at mixer input is lower than RF input
signal frequency.
IF
= 133.333 kHz or 150 kHz. The mixer architecture provides inherent image
IF
= 133.333 kHz or 150 kHz is chosen depends on bits FREF[1:0].
Rev. 01 — 11 April 2006
Low-power AM/FM stereo radio for handheld applications
© Koninklijke Philips Electronics N.V. 2006. All rights reserved.
LNA input
TEA5777
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